Effect Of Bagging On The Wine Grape And Wine

This research was carried out in Penglai from March to November 2009. Clusters of Vitis vinifera L. cv. Chardonnay and Cabernet Sauvignon were bagged and debagged in two different times with two types of paper bags: bagging in occurrence period and debagging one weeks before harvest for white bag (T1); bagging in occurrence period and debagging two weeks before harvest for white bag (T2); bagging in veraison and debagging one weeks before harvest for white bag (T3); bagging in veraison and debagging two weeks before harvest for white bag (T4); bagging in occurrence period and debagging one weeks before harvest for yellow bag (T5); bagging in occurrence period and debagging two weeks before harvest for yellow bag (T6); bagging in veraison and debagging one weeks before harvest for yellow bag (T7); bagging in veraison and debagging two weeks before harvest for yellow bag (T8) and compared with unbagging(CK). In order to lay the foundation for the bagging technology of wine grape in the rainy regions during the maturity, the qualities of mature berries of Cabernet Sauvignon were determined. And the qualities of dry white wine in Chardonnay and dry red wine in Cabernet Sauvignon brewed by traditional technology after harvest were also determined.The main conclusions were as follows:1. It could effectively prevent fruit diseases by bagging. The earlier and the longer clusters were bagged, the better effect would be.2. The maturity of Cabernet Sauvignon was delayed by bagging. The maturity of Chardonnay was promoted by white bags, while delayed by yellow bags.3. The reducing sugar, titration acid, total phenol, tannin and total anthocyanin of mature berries were decreased by bagging. The earlier clusters were bagged, the lower sugar content would be.4. The composition of anthocyanin and individual phenolics of berries were changed. The percentage of nonflavonoids content in Cabernet Sauvignon berries was improved by using white bags, while the percentage of flavonoids rose with yellow bags.5. The total phenol, tannin and protein of wines were increased by bagging. The percentage of nonflavonoids content in wines was improved by using bags. The content of flavonoids in dry white wine in Chardonnay was improved by yellow bags. And the white bags were better than yellow bags to increase nonflavonoids in dry red wine in Cabernet Sauvignon. 6. Bagging can increase the color intensity of dry red wine in Cabernet Sauvignon. There was very significant difference among the time of bagging and debagging. The best treatment for increasing color intensity was that bagging in the occurrence period and two weeks before harvest time separately (T2, T4).7. Esters and alcohols were the most important aromas in the experimental wines. It could increase the total concentration of aromatic components and the percentage of alcohols by bagging. Howevre, the percentage of esters were decreased by bagging. Fruits bagging reduced the content of carbonyl compound and terpenes in dry white wines in Chardonnay. Compared with CK, the content of carbonyl compound and terpenes were obvious increased in dry red wine of Cabernte Sauvignon.